Bark anatomy of the Fraxinus species (Oleaceae) in connection with their systematic position

摘要

The anatomy of the bark of annual stems, perennial branches and trunks in 19 species of Fraxinus has been studied. It has been determined that differences are more clearly noticeable at the level of subgenus, than that of section, and the taxonomic importance have the types of sieve plates and rays. In accordance with the code of the specialization of phloem, more evolutionary advanced phloem is found in the subgenus Fraxinaster than in the subgenus Ornaster.